/*********************************************************************
 * Copyright (C) 2002 Andrew Khan
 * <p>
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * <p>
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * <p>
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ***************************************************************************/

package jxl.read.biff;

import jxl.BooleanCell;
import jxl.BooleanFormulaCell;
import jxl.CellType;
import jxl.biff.FormattingRecords;
import jxl.biff.FormulaData;
import jxl.biff.WorkbookMethods;
import jxl.biff.formula.ExternalSheet;
import jxl.biff.formula.FormulaException;
import jxl.biff.formula.FormulaParser;
import jxl.common.Assert;

/**
 * A boolean formula's last calculated value
 */
class BooleanFormulaRecord extends CellValue
        implements BooleanCell, FormulaData, BooleanFormulaCell {
    /**
     * The boolean value of this cell.  If this cell represents an error,
     * this will be false
     */
    private boolean value;

    /**
     * A handle to the class needed to access external sheets
     */
    private ExternalSheet externalSheet;

    /**
     * A handle to the name table
     */
    private WorkbookMethods nameTable;

    /**
     * The formula as an excel string
     */
    private String formulaString;

    /**
     * The raw data
     */
    private byte[] data;

    /**
     * Constructs this object from the raw data
     *
     * @param t the raw data
     * @param fr the formatting records
     * @param si the sheet
     * @param es the sheet
     * @param nt the name table
     */
    public BooleanFormulaRecord(Record t, FormattingRecords fr,
                                ExternalSheet es, WorkbookMethods nt,
                                SheetImpl si) {
        super(t, fr, si);
        externalSheet = es;
        nameTable = nt;
        value = false;

        data = getRecord().getData();

        Assert.verify(data[6] != 2);

        value = data[8] == 1 ? true : false;
    }

    /**
     * Interface method which Gets the boolean value stored in this cell.  If
     * this cell contains an error, then returns FALSE.  Always query this cell
     *  type using the accessor method isError() prior to calling this method
     *
     * @return TRUE if this cell contains TRUE, FALSE if it contains FALSE or
     * an error code
     */
    public boolean getValue() {
        return value;
    }

    /**
     * Returns the numerical value as a string
     *
     * @return The numerical value of the formula as a string
     */
    public String getContents() {
        // return Boolean.toString(value) - only available in 1.4 or later
        return (new Boolean(value)).toString();
    }

    /**
     * Returns the cell type
     *
     * @return The cell type
     */
    public CellType getType() {
        return CellType.BOOLEAN_FORMULA;
    }

    /**
     * Gets the raw bytes for the formula.  This will include the
     * parsed tokens array
     *
     * @return the raw record data
     */
    public byte[] getFormulaData() throws FormulaException {
        if (!getSheet().getWorkbookBof().isBiff8()) {
            throw new FormulaException(FormulaException.BIFF8_SUPPORTED);
        }

        // Lop off the standard information
        byte[] d = new byte[data.length - 6];
        System.arraycopy(data, 6, d, 0, data.length - 6);

        return d;
    }

    /**
     * Gets the formula as an excel string
     *
     * @return the formula as an excel string
     * @exception FormulaException
     */
    public String getFormula() throws FormulaException {
        if (formulaString == null) {
            byte[] tokens = new byte[data.length - 22];
            System.arraycopy(data, 22, tokens, 0, tokens.length);
            FormulaParser fp = new FormulaParser
                    (tokens, this, externalSheet, nameTable,
                            getSheet().getWorkbook().getSettings());
            fp.parse();
            formulaString = fp.getFormula();
        }

        return formulaString;
    }
}

